Rock drilling apparatuses normally comprise a carrier onto which a boom at its one end has been turnably assembled in vertical and horizontal directions in relation to the carrier. Further, at the other end of the boom there is a feed beam for a rock drill. At the front end of the feed beam there is typically a support, which is pressed against the surface before drilling in order to keep the feed beam steadily in its position during the drilling.
Typically, the feed beam is orientated before pushing the support against the surface to its designed direction so that the hole should be drilled according to a predesigned plan precisely where the designer has intended to. However, there may remain errors in the drilling. Deviations in the orientation are due to physical facts, which apply as the support is pushed against the surface and after that.
When pushing the support against the surface, the force pushing the feed beam against the rock may change the position and the alignment of the apparatus, which changes the direction of the boom and the feed beam. Also, the forces may bend the boom, which may further increase the deviation. As a result, the directions of the holes may be incorrect.
An aspect of the disclosure is to provide a rock drilling apparatus and a method for controlling the orientation of the feed beam, in which the accuracy of the drilling is improved.
The basic idea in the rock drilling apparatus is that the arrangement is configured, on the basis of the parameters affecting the orientation, to define the orientation change caused by driving the support onto the ground. The orientation of the boom and feed beam is automatically adjusted before applying drilling force to compensate for the orientation change caused by supporting the drilling boom onto the ground.
In one embodiment of the rock drilling apparatus, the apparatus is configured to define the orientation change on the basis of one or more of the orientation of the boom, orientation of the feed beam, direction of the hole, and direction and inclination of the carrier.
In another embodiment of the rock drilling apparatus, the apparatus is configured, on the basis of the defined orientation change, to automatically change the orientation of the boom and feed beam before the support is driven onto the ground.
In still another embodiment of the rock drilling apparatus, the apparatus is configured, on the basis of the defined orientation change, to automatically change the orientation of the boom and feed beam after the support is driven onto the ground.
In still another embodiment of the rock drilling apparatus, the apparatus is configured, on the basis of the defined orientation change, to automatically change the orientation of the boom and feed beam during the driving of the support onto the ground.
Further, the method includes the steps of defining the orientation of the boom and feed beam, defining, on the basis of parameters affecting the orientation change, the orientation change caused by driving the support to the ground, and adjusting automatically the orientation of the boom and feed beam to compensate for the orientation change before applying drilling force.
In one embodiment of the method, the defining of the orientation change is performed on the basis of one or more of the orientation of the boom, orientation of the feed beam, direction of the hole, and direction and inclination of the carrier.
In another embodiment of the method, the orientation change is done on the basis of parameters defining the changes of the positions of the carrier, boom, and feed beam, when the rock drilling apparatus is set to a support position for drilling after having driven the support into the ground.
In still another embodiment of the method, the adjustment of the orientation of the boom and feed beam is done before driving the support into the ground.
In still another embodiment of the method, the adjustment of the orientation of the boom and feed beam is done during the driving of the support onto the ground.
In yet another embodiment of the method, the orientation is done by using the drilling data of the hole to be drilled.